"The New York City Department of Transportation will replace some 250,000 conventional street- and highway-lighting units with LED units over the next two years. When it does, however, the new lighting will comply with existing standards that do not consider the specific attributes of LED lighting. As a result, the new lighting may actually provide less visibility and save less energy than it otherwise could, and it will probably produce more glare," Parks said.

Feb 24, 2015

The industrywide shift to LED lighting is happening at a faster pace than standards-development, leading to a mismatch between the technology and the guidelines by which it is being applied, particularly in the case of guidelines followed by owners of outdoor lighting systems who tend to follow standards as a shield from liability lawsuits, according to a panel of three lighting experts in a discussion recently posted on the National Lighting Bureau’s website.

Here’s an excerpt from the Silver Spring, Md.-based NLB’s release announcing the availability of the panel transcript:

[Bob Parks, executive director of the Smart Outdoor Lighting Alliance,] referred to new research showing that some outdoor lighting provides better nighttime visibility when it is not uniform, because uniformity reduces the contrast that is an essential element of good visibility. Mr. Parks said the same research also showed that illumination levels could be reduced by as much as half the contemporary recommendations, with no reduction in visibility, when the illumination is provided by broad-spectrum, white-light sources, like some LEDs. Mr. Parks opined that contemporary standards are out of date because they specify illumination levels and uniformity that are too high for broad-spectrum white light. Nonetheless, because complying with standards is a shield against lawsuits alleging that lighting was inadequate and therefore caused or contributed to an accident, those who own or operate outdoor-lighting systems conform to standards.

The two other panelists – Mark Lien, director of government and industry relations for Osram Sylvania, and Janet Lennox Moyer, a lighting designer and founder of the International Landscape Lighting Institute – further highlight the potential of dynamic spectral tuning of outdoor lighting to improve visibility and reduce glare at lower power consumption levels, but the technology won’t be widely used until standards exist.